GEOLOGY OF THE FOURTH DISTRICT. 



ORGANIC REMAINS OF THE CLINTON GROUP. 



No. 7. —No. 17, page 72. 

 Fig. 1. Strophomena elegant ula, II. Shell with elevated ribs and fine striae between. It bears 



a considerable analogy to S. sericea and S. transversalis, but is quite distinct 



from either. Sodus Point. 

 Fig. 2. Strophomena corrugata, C. (Jour. Acad. Nat. Science, Vol. 8, p. 25(5, pi. 14, fig. 8.) 



Rochester. 

 Fig. 3. S. cornuta, H. A small neatly striated shell, armed with small rigid spines on the 



hinge line. Sodus Point. 

 Fig. 4. Atrypa hemispherica, (Silurian Researches, pi. 20. fig. 7.) Abundant in the green 



shale at Rochester. 

 Fig. 5. Littorina cancellata, II. Young shell. Sodus Point. 

 Fig. 6. — — " Old shell, with the markings worn off. 



Fig. 7. Posidonia? alata, H. Green shale, Rochester. 

 Fig. 8 and 8 a. Atrypa affinis ? Old and young shells. Sodus Point. 

 Fig. 9. Calymene? trisulcata, H. A small trilobite, with three furrows on each side of the 



middle lobe of the head. Rochester. 

 Fig. 10. Agnostus latum Green shale, Rochester. 

 Fig. 11. Tentaculites minutus. 

 Fig. 12. Graptolites Clintonensis . An abundant form in the upper green shale of the group. 



Sodus Point. 



No. 8. — No. 18, page 76. 

 Fig. 1. Orthonata curta, H. 

 Fig. 2. Nucula machcerceformis, II. 

 Fig. 3. Cypricardia obsolcta, H. 

 Fig. 4. Nucula mactrceformis, H. 

 Fig. 5. Avicida leptonota, H. \ Shale of the Wolcott ore bed in Wayne county. 



Fig. 6. Cypricardia? angusta, II. 

 Fig. 7. Lingula elliptica, H. 

 Fig. 8. L. oblata,. II. 



Fig. 9. L. acutirostra, H. 



No. 9. — No. 19, page 77. 

 Fig. 1. Fucoides biloba, Vanuxem (Geological Report, page 79). 

 Fig. 2. Tail of Ilemicrypturus. " " 



Fig. 3. Smooth crinoidal joint. " " 



Fig. 4. Lingula oblonga, C. (Annual Geol. Report, page 65.) 



L. Clintoni, Vanuxem (Report, page 78). 



Fig. 5. Strophomena depressa. (Leptana depressa, Dalman.) 



